This year's first hornworm discovery

They are cocoons and I believe they continue to feed off the caterpillar -- that's why the caterpillar stays/are left alive and even moves around sometimes. It's a great horror flick concept "borrowed" by many screen writers.

...and exactly. Killing the caterpillar may prevent the wasps from maturing and kill them or force them to eclose prematurely.

-- Applestar, who is STILL very irritated by the extremely talented author/illustrator Eric Carle who has been singlehandedly sabotaging children's education -- A butterfly caterpillar makes a CHRYSALIS So was that a very hungry BUTTERFLY caterpillar or a MOTH caterpillar?